diff options
| author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2008-09-25 20:59:12 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2008-09-25 23:39:24 +0100 |
| commit | 56f55f8b58a02e95b401cb50df05086cabeaeeb5 (patch) | |
| tree | 3be7e3383157c731178ca447008c0e7c236bfbfc | |
| parent | afd1a321c49a250dab97cef6f2d3c3c9b9d0174a (diff) | |
[ARM] dma: provide a better dma_map_page() implementation
We can translate a struct page directly to a DMA address using
page_to_dma(). No need to use page_address() followed by
virt_to_dma().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | arch/arm/common/dmabounce.c | 13 | ||||
| -rw-r--r-- | arch/arm/include/asm/dma-mapping.h | 11 |
2 files changed, 23 insertions, 1 deletions
diff --git a/arch/arm/common/dmabounce.c b/arch/arm/common/dmabounce.c index 35c72bcf3d0..c7f23ced0a3 100644 --- a/arch/arm/common/dmabounce.c +++ b/arch/arm/common/dmabounce.c @@ -412,6 +412,19 @@ dma_map_single(struct device *dev, void *ptr, size_t size, return dma_addr; } +dma_addr_t dma_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, + enum dma_data_direction dir) +{ + dev_dbg(dev, "%s(page=%p,off=%#lx,size=%zx,dir=%x)\n", + __func__, page, offset, size, dir); + + BUG_ON(dir == DMA_NONE); + + return map_single(dev, page_address(page) + offset, size, dir); +} +EXPORT_SYMBOL(dma_map_page); + /* * see if a mapped address was really a "safe" buffer and if so, copy * the data from the safe buffer back to the unsafe buffer and free up diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index eff954852c2..856ee1bdee5 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -227,13 +227,22 @@ extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_d * can regain ownership by calling dma_unmap_page() or * dma_sync_single_for_cpu(). */ +#ifndef CONFIG_DMABOUNCE static inline dma_addr_t dma_map_page(struct device *dev, struct page *page, unsigned long offset, size_t size, enum dma_data_direction dir) { - return dma_map_single(dev, page_address(page) + offset, size, dir); + if (!arch_is_coherent()) + dma_cache_maint(page_address(page) + offset, size, dir); + + return page_to_dma(dev, page) + offset; } +#else +extern dma_addr_t dma_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, + enum dma_data_direction dir); +#endif /** * dma_unmap_single - unmap a single buffer previously mapped |